Except nobody paid.
* offer a $100 credit to start off.
* offer more services than just a tweet if successful - for example a very simple feedback widget that shows up.
* charge only for delaying ship dates, but not for changing what is being shipped, or for minor delays (say within a week).
* don't charge if the person accepts public humiliation with a tweet saying "I sucked and did not ship my planned item.".
http://bestofcalvinandhobbes.com/2011/10/a-swifty-kick-in-th...
Except nobody paid.